What is H.264 - SVC?
an IP network-friendly coding approach that can satisfy underlying transmission requirements ranging all the way from HDTV over the enterprise LAN to two-way video chat sessions over an unreliable cell phone network

WhySVC?
video conferencing for the Internet that works like the Internet

Better VidyoConferencing Experience
improved quality through the utilization of high-reliability and low-reliability channels

Scalable video coding (SVC), a technique that enables a video stream to be broken into multiple resolutions, quality levels and frame rates, is appealing for applications where the bandwidth available cannot be guaranteed - for example Internet video, video telephony, and wireless communications.

The purpose of any video compression algorithm is to exploit both the spatial and temporal redundancy of video information so that acceptable video quality can be received at the far end while using as few bits as possible to transmit the signal. A non-scalable video encoder generates a single compressed bitstream. A scalable video encoder compresses a raw video sequence into multiple layers (see diagram). One of the compressed layers is the base layer. The base layer can be independently decoded and can provide a relatively low level of video quality. Additional compressed layers are enhancement layers that provide additional quality to the received video stream. Enhancement layers can be decoded only in conjunction with the base layer. The complete bitstream would consist of the base layer and all the enhancement layers and would provide the very best video quality.